********** upgrade of my cheque account

FNB upgraded my account to premium without my permission. On 24 October 2018 I logged a call with FNB and was assisted by Sekgitlela who told my query will be escalated by Rebecca Ntuli and she will call me within an hour (Call reference was RI ********** 5225 9:37, case number given was ********** ). I called to make a follow-up on the 5th November 2018 at 9:27 and was assisted by Jabulani who told me my case was escalated on the 25th October 2018 to the complaints department and was promised to be called back by Rebecca before the end of day (Call reference was RP ********** 7632). I called on the 22 November 2018 at 9:57 and spoke to Timothy and he said he said he will put me through to SSCC in Kent department but unfortunately I was put through to the lost cards who couldn't help me. I want the full investigation report of why and who upgraded my account without approval.